Tuesday, February 5, 2013

No More Nitrogen

No More Nitrogen

Lesley Stein

I sit down, brainstorm,
come up with an awesome topic, begin writing my first blog (a week before its
due because I'm so stoked on my topic) and lo and behold a fellow grad student (Kaitlin
Johnson) has written about the same topic and steals my thunder!Kaitlin does a wonderful job also explaining
nitrogen narcosis, however to switch things up a bit I will also be discussing
decompression sickness.

SCUBA has become my greatest passion ever since I was certified. I feel at peace underwater,
free of stress, hearing only my breathing, and seeing only a world
which fascinates me. However this thrilling hobby can have serious repercussions.
Nitrogen narcosis and decompression sickness have always tripped me out
because some of my closest friends have experienced them. First lets dive
into nitrogen narcosis.

What Is Nitrogen Narcosis?

Nitrogen narcosis is an
altered state of mind caused by breathing nitrogen at a high partial pressure.
Partial pressure is the ratio of pressure exerted by one gas into a
mixture of gasses. In a diver's breathing tank the concentration of a
gas, such as nitrogen, changes as the diver uses the gas to breathe and his/her
change depth in the water. Nitrogen narcosis occurs when a diver breathes
a higher percentage of nitrogen due to increased depths. Therefore, the
deeper a diver descends and the higher percentage of gas creates a greater
partial pressure....resulting in getting "narked" up.

What Are The Mechanisms
Behind Narcosis?

The specific mechanisms of
nitrogen narcosis are not well understood. The most supported idea is
that dissolved gas in nerve membranes causes short-term interference in nerve
transmissions. Increasing the amount of gas dissolved in nerve cell
membranes can change the normal ion permeability of a neural cell's lipid
bilayer. The lipid bilayer may allow ions through that normally would not
and potentially block others that naturally would pass therefore, allowing
nitrogen into the bloodstream at high pressures.

This shows as a
diver descends the total pressure of gasses increase, in turn increasing each
gas proportionally.

What Are The Effects Of
Narcosis?

I have personally
experienced getting "narked" up. Prior to diving I was timed to find the solution to a simple PVC pipe puzzle. The test consisted of connecting 8
pieces to fit a square. On land it took me 8 seconds, however, once I was
95 feet under water and attempted the puzzle it took me one minute and 15
seconds. I was experiencing slight nitrogen narcosis. What did it
feel like? More like what didn't it feel like. I just didn't really
care about anything, I wasn't cold, I didn't care about a stupid little puzzle,
I was feeling a little tipsy, and all I wanted to do was bob up and down based
on my breathing. Luckily this wasn't an extreme case of narcosis and my
friends noticed my struggle with the puzzle and kept an eye on me until everyone
completed the puzzle and surfaced together. Other people have noticed
effects such as lightheadedness, feeling drunk, loss of reasoning, over
confidence, difficulty concentrating, decreased coordination, hallucinations,
coma, or in some cases death. The main way it can lead to death is by
diving alone, experiencing narcosis, and not having the ability to mentally
recognize it or have the “will power” to take correct action. This can lead to
staying under water longer than you have enough air for. That is one among many reasons why you should never dive alone.

Ways To Reduce Narcosis/
Treatment

Several ways to reduce
nitrogen narcosis symptoms are to be motivated to complete specific tasks,
acclimate yourself multiple experiences of narcosis, or having a high tolerance
of alcohol consumption. Interestingly, it has been shown that a diver
with a "high tolerance" of alcohol consumption has a higher tolerance
to narcosis.

A nickname for the effects
of Nitrogen Narcosis is Martini's Law. Meaning every 10 meters is
equivalent to drinking one martini. Therefore, in my case according to
Martini's Law I had 3 martinis, which kind of makes sense...

The best method to treat
narcosis is slowly ascending to shallower depths, keeping in mind decompression
limits.Which is a great segway to discuss
decompression sickness.

Decompression sickness

Often non-scuba divers (or
also those that should not be diving) get nitrogen narcosis and decompression
sickness confused with each other.In
reality the two are very different, nitrogen narcosis involves being at depth (usually 100ft or deeper) and is experienced during a dive, whereas
decompression sickness involves how quickly a diver ascends to the surface and
is expressed after a dive.A diver can
experience one condition during a dive or if extremely unfortunate both, but
one is not dependent on the other.

What Is Decompression Sickness?

Decompression Sickness
(DCS) also called the "bends" is an illness caused by nitrogen being absorbed by and
remaining in the blood and fatty tissues caused by ambient water pressure.Bubbles from nitrogen grow in ones tissues
and causes local damage. DCS got the
nickname the "bends"; by these bubbles forming in the spinal cord, which would
cause inflation and could cause a person to develop arthritis, leading them to
be bent over.Normally when a diver
ascends properly (no more than 30 feet per minute) the pressure around the
diver decreases.This allows nitrogen
molecules out of the cells and into the tissues; they enter the
bloodstream and are transported to the lungs to be released by exhaling.However, DCS occurs when pressure around the
body is released too quickly, in turn creating bubbles within the tissues.Bubbles are created when large amounts of
nitrogen molecules are released from cells; these molecules are attracted to
one another creating a bubble.The bubbles
have surface tension which traps them in the lining of the tissue.

What Are The Symptoms?

Symptoms usually occur 30
minutes after a dive.

·Pain in joints, muscles,
arms, legs, or torso

·Inflammation

·Itchy skin

·Tingling

·Shortness of breathe

·Ringing in ears

What To Do When You Have DCS?

It depends on the degree of
DCS; there is a Type 1 and a Type 2. Mild cases are Type 1and can be treated
with an oxygen facemask and symptoms may simply go away.Type 2 DCS is more severe and
requires going into a hyperbaric chamber.Type 1 is usually dealing with the peripheral nervous system, while Type
2 usually involves the central nervous system.So what exactly is a hyperbaric chamber?

A hyperbaric chamber is a large
closed contain that people can walk in and out of that holds gases at a certain
pressure.The purpose of the chamber is
to allow the diver to complete their safety stops.Safety stops while scuba diving are meant to
allow the nitrogen to come out of the tissues and back into the
bloodstream.The appropriate amount of
pressure is applied along with pure oxygen.The oxygen is taken up into the blood faster in the chamber, which helps
repair cells.The time spent in the
chamber depends on the amount of nitrogen in one’s body, sometimes as long as
18 hours.Overall, Scuba diving is an
amazing hobby, but it is important to understand the dangers involved with
breathing under water.

1 comment:

More fun things that can happen to you on a dive... Still, with all the marine people around Cal Poly, I definitely want to check out diving while I'm here. I was wondering why there is a correlation between alcohol tolerance and nitrogen narcosis tolerance. Is there a similar mechanism for processing excess nitrogen and excess alcohol? Interesting blog!